Semiconductor device and method of fabricating the same

Abstract

Provided are a semiconductor device and a method of fabricating the semiconductor device. The semiconductor device includes a first conductive well region in a semiconductor substrate and a second conductive well region on or in the first conductive well region. A gate electrode is in a trench on a gate insulation layer, and the trench is in the second conductive region and the first conductive well region. A drain includes a drain insulation layer, a (polysilicon) shield layer, and drain plug. The drain insulation layer is in a trench in the second conductive region and the first conductive well region. The shield layer encloses the drain plug. A lower portion of the drain plug contacts the second conductive well region. A first conductive source region is at a side of the gate electrode.

1. A semiconductor device comprising:
 a first conductive well region in a semiconductor substrate; 
 a second conductive well region on the first conductive well region; 
 a gate electrode in a first trench on a gate insulation layer in the first trench, the first trench being in the second conductive region and at least part of the first conductive well region; 
 a drain including a conductive shield layer, a drain insulation layer, and a drain plug, the drain insulation layer being in a second trench in the second conductive region and at least part of the first conductive well region, the conductive shield layer enclosing the drain plug, and the drain plug being in contact with the second conductive well region; and 
 a first conductive source region at a side of the gate electrode. 
 
     
     
       2. The semiconductor device according to  claim 1 , wherein the drain further includes a silicon oxide layer between the drain plug and the conductive shield layer. 
     
     
       3. The semiconductor device according to  claim 1 , further comprising a first conductive high-concentration impurity region between the drain plug and the first conductive well region. 
     
     
       4. The semiconductor device according to  claim 1 , wherein the drain insulation layer is on a side and a bottom of the conductive shield layer. 
     
     
       5. The semiconductor device according to  claim 1 , wherein the drain insulation layer comprises an oxide layer. 
     
     
       6. The semiconductor device according to  claim 1 , further comprising a first conductive buried layer under the first conductive well region. 
     
     
       7. The semiconductor device according to  claim 1 , wherein the first conductive source region is at opposite sides of the gate electrode. 
     
     
       8. The semiconductor device according to  claim 1 , further comprising a second conductive body region at a side of the first conductive source region.